... one source said Facebook makes twice the ad revenue from its API as from direct sales. Twitter seems very serious about an ad API’s potential. Mention of the ad API "is plastered over every single whiteboard in Twitter HQ," said one source.

Twitter Ads. Twitter reserves the right to serve advertising via its APIs ("Twitter Ads"). If you decide to serve Twitter Ads once we start delivering them, we will share a portion of advertising revenue with you per our then-current terms and conditions.

The average Twitter user follows five or more brands. Users who primarily access Twitter on mobile are 96% more likely to follow 11 or more brands. They are also 58% more likely to recall seeing an ad on Twitter than the average Twitter user.